The State Department said Friday U.S. officials are "profoundly concerned" about reports that Rwandan troops have entered the eastern part of the Democratic Republic of Congo. A senior State Department envoy has been sent to the area for talks in both countries.

Reports from U.N. peacekeepers that Rwandan troops have been spotted in the eastern Congo have spurred concerns in Washington and elsewhere about a possible renewal of central African warfare.

The conflict that began in 1998 dragged on for nearly five years, drew in forces of five African countries, and left the Democratic Republic of Congo (DRC) divided and battered.

Rwanda denies moving troops into the territory of its larger neighbor, but its President, Paul Kigame, has warned in recent days that his country would act against Rwandan Hutu rebels taking shelter in eastern Congo.

At a news briefing, State Department Spokesman Richard Boucher said the reported troop movements, while unverified, are of profound concern to the United States:

"While we don't have confirmation of large-scale Rwandan troop movements into Congo, we do want to state unequivocally that we are opposed to unilateral military actions that are contrary to the numerous agreements signed by the parties, and contrary to the Security Council resolutions passed over the last five years," said Mr. Boucher.

Mr. Boucher said the United States shares Rwanda's concerns about the threat posed by armed groups in eastern Congo, but believes the best way to deal with it is through diplomacy and not armed action.

He said U.S. officials have been working for several months on ministerial level meetings among the countries involved, and that the process will continue with a mission to Rwanda and the DRC by Donald Yamamoto, Deputy Assistant Secretary of State for African Affairs.

Mr. Yamamoto left Washington on the mission Thursday with an initial stop in Eritrea. He is due in Kinshasa over the weekend and will go to Kigali, the Rwandan capital next week.

Rwanda invaded the eastern Congo twice during the past decade to hunt down Rwandan Hutu rebels responsible for the 1994 genocide campaign in Rwanda against minority Tutsis and Hutu moderates.

The latest developments have also promoted appeals for dialogue and restraint from the African Union and European Union chief diplomat Javier Solana.